Numerical investigation of high-temperature effects in the UTIAS–RPI hypersonic impulse tunnel

1991 ◽  
Vol 69 (7) ◽  
pp. 897-918 ◽  
Author(s):  
C. P. T. Groth ◽  
J. J. Gottlieb ◽  
P. A. Sullivan
Keyword(s):  
High Temperature ◽  
Test Section ◽  
Flow Analysis ◽  
Operating Conditions ◽  
Vibrational Modes ◽  
Blow Down ◽  
Riemann Solvers ◽  
University Of Toronto ◽  
High Mach ◽  
The University

The hypersonic impulse tunnel of the University of Toronto Institute for Aerospace Studies (UTIAS) and Ryerson Polytechnical Institute (RPI) is a short-duration blow-down experimental wind tunnel capable of producing high-Mach-number flows (Ma ≈ 8). A generalized quasi-one-dimensional nonstationary flow analysis and associated total-variation-diminishing (TVD) finite-difference solution schemes, including aproximate Riemann solvers, are presented for predicting the high-temperature flows in such facilities. The analysis is used to investigate the operation of the UTIAS–RPI facility and produce performance data that are not always easily determined or available from experimental measurements. The thermodynamic state of the nozzle-exit flow and high-temperature or real-gas effects are assessed for this facility under various operating conditions. Numerical results, coupled with additional comparisons with available experimental data, demonstrate the range of test-section flows that may be achieved. They also illustrate that for typical operating conditions, the air (working gas used in UTIAS–RPI facility) freezes in the nozzle very close to the throat and results in test-section flows with considerable energy bound in the vibrational modes of the nitrogen (N2) and oxygen (O2) molecules. In particular, the test-section temperatures associated with the vibrational modes of N2 are only marginally less than barrel-end stagnation temperatures, whereas the vibrational temperatures of O2, although lower than stagnation temperatures, are still much higher than the predicted translational–rotational temperatures.

Investigation of Brush Seal Flow Characteristics Using Bulk Porous Medium Approach

2005 ◽  
Vol 127 (1) ◽  
pp. 136-144 ◽  
Author(s):  
Yahya Dogu
Keyword(s):  
Porous Medium ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Operating Conditions ◽  
Force Balance ◽  
Complex Flow ◽  
Blow Down ◽  
Permeability Coefficients ◽  
Backing Plate ◽  
Brush Seal

The flow behavior through a brush seal has been investigated by developing a flow analysis procedure with a porous medium approach. In order to increase the brush seal performance and use at more severe operating conditions, the complex flow in the bristle pack has become the major concern affecting seal features such as blow-down, hang-up, hysteresis, and bristle flutter. In this study, an axisymmetric CFD model is employed to calibrate anisotropic permeability coefficients for the bristle pack based on available experimental data: leakage, axial pressure on the rotor surface, and radial pressure on the backing plate. A simplified form of the force balance equation is introduced for the flow in the porous bristle pack. Different sets of permeability coefficients are defined for the fence height region below the seal backing plate and the upper region of the seal to correlate the different physical structures and behavior of these regions during operation. The upper region is subject to more stiffening due to backing plate support while the fence height region is free to spread and bend in the axial direction. It is found that flow resistance for the upper region should be 20% higher than the fence height region in order to match the experimental pressure within the bristle pack. Analysis results prove that the brush seal is well represented as a porous medium with this approach. Based on the model developed, characteristic flow and pressure fields in the entire bristle pack have been explored.

Investigation of Brush Seal Flow Characteristics Using Bulk Porous Medium Approach

2003 ◽  
Author(s):  
Yahya Dogu
Keyword(s):  
Porous Medium ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Operating Conditions ◽  
Force Balance ◽  
Complex Flow ◽  
Blow Down ◽  
Permeability Coefficients ◽  
Backing Plate ◽  
Brush Seal

The flow behavior through a brush seal has been investigated by developing a flow analysis procedure with a porous medium approach. In order to increase the brush seal performance and use at more severe operating conditions, the complex flow in the bristle pack has become the major concern affecting seal features such as blow-down, hang-up, hysteresis and bristle flutter. In this study, an axi-symmetric CFD model is employed to calibrate anisotropic permeability coefficients for the bristle pack based on available experimental data; leakage, axial pressure on the rotor surface and radial pressure on the backing plate. A simplified form of the force balance equation is introduced for the flow in the porous bristle pack. Different sets of permeability coefficients are defined for fence height region below the seal backing plate and the upper region of the seal to correlate the different physical structures and behavior of these regions during operation. The upper region is subject to more stiffening due to backing plate support while fence height region is free to spread and bend in the axial direction. It is found that flow resistance for upper region should be 20% higher than fence height region in order to match the experimental pressure within the bristle pack. Analysis results prove that the brush seal is well represented as a porous medium with this approach. Based on the model developed, characteristic flow and pressure fields in the entire bristle pack have been explored.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

Development of the University of Toronto Skull Base Inventory (UT-SBI) Quality-of-Life Questionnaire

Skull Base ◽  
2009 ◽  
Vol 19 (03) ◽  
Author(s):  
John de Almeida ◽  
Allan Vescan ◽  
Jolie Ringash ◽  
Patrick Gullane ◽  
Fred Gentili ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Skull Base ◽  
Life Questionnaire ◽  
Quality Of Life Questionnaire ◽  
University Of Toronto ◽  
The University

Disruptive innovation and operationalization in local and sustainable food systems: Examining the University of Toronto-Local Food Plus partnership

2019 ◽  
Vol 6 (1) ◽  
pp. 120-139
Author(s):  
Lori Stahlbrand
Keyword(s):  
Food Systems ◽  
Large Scale ◽  
Food System ◽  
Local Food ◽  
Disruptive Innovation ◽  
Government Support ◽  
Sustainable Food ◽  
University Of Toronto ◽  
The University

This paper traces the partnership between the University of Toronto and the non-profit Local Food Plus (LFP) to bring local sustainable food to its St. George campus. At its launch, the partnership represented the largest purchase of local sustainable food at a Canadian university, as well as LFP’s first foray into supporting institutional procurement of local sustainable food. LFP was founded in 2005 with a vision to foster sustainable local food economies. To this end, LFP developed a certification system and a marketing program that matched certified farmers and processors to buyers. LFP emphasized large-scale purchases by public institutions. Using information from in-depth semi-structured key informant interviews, this paper argues that the LFP project was a disruptive innovation that posed a challenge to many dimensions of the established food system. The LFP case study reveals structural obstacles to operationalizing a local and sustainable food system. These include a lack of mid-sized infrastructure serving local farmers, the domination of a rebate system of purchasing controlled by an oligopolistic foodservice sector, and embedded government support of export agriculture. This case study is an example of praxis, as the author was the founder of LFP, as well as an academic researcher and analyst.

Buddhist, a Christian, and an Atheist Walk into a Classroom

2013 ◽  
Vol 42 (3) ◽  
pp. 37-42
Author(s):  
Ken Derry
Keyword(s):  
First Year ◽  
Specific Relation ◽  
University Of Toronto ◽  
Central Focus ◽  
The University

Although none of the articles in this issue on the topic of religion and humor are explicitly about teaching, in many ways all of them in fact share this central focus. In the examples discussed by the four authors, humor is used to deconstruct the category of religion; to comment on the distance between orthodoxy and praxis; to censure religion; and to enrich traditions in ways that can be quite self-critical. My response to these articles addresses each of the above lessons in specific relation to experiences I have had in, and strategies I have developed for, teaching a first-year introductory religion course at the University of Toronto.

63. Developing a program for resident wellness at the postgraduate medical education office, University of Torontos

2007 ◽  
Vol 30 (4) ◽  
pp. 63 ◽  
Author(s):  
S. Edwards ◽  
S. Verma ◽  
R. Zulla
Keyword(s):  
Mental Health ◽  
Medical Education ◽  
Stress Management ◽  
Residency Training ◽  
Medical Training ◽  
Postgraduate Medical Education ◽  
Program Directors ◽  
University Of Toronto ◽  
Resident Wellness ◽  
The University

Prevalence of stress-related mental health problems in residents is equal to, or greater than, the general population. Medical training has been identified as the most significant negative influence on resident mental health. At the same time, residents possess inadequate stress management and general wellness skills and poor help-seeking behaviours. Unique barriers prevent residents from self-identifying and seeking assistance. Stress management programs in medical education have been shown to decrease subjective distress and increase wellness and coping skills. The University of Toronto operates the largest postgraduate medical training program in the country. The Director of Resident Wellness position was created in the Postgraduate Medical Education Office to develop a systemic approach to resident wellness that facilitates early detection and intervention of significant stress related problems and promote professionalism. Phase One of this new initiative has been to highlight its presence to residents and program directors by speaking to resident wellness issues at educational events. Resources on stress management, professional services, mental health, and financial management have been identified and posted on the postgraduate medical education website and circulated to program directors. Partnerships have been established with physician health professionals, the University of Toronto, and the Professional Association of Residents and Internes of Ontario. Research opportunities for determining prevalence and effective management strategies for stress related problems are being identified and ultimately programs/resources will be implemented to ensure that resident have readily accessible resources. The establishment of a Resident Wellness Strategy from its embryonic stags and the challenges faced are presented as a template for implementing similar programs at other medical schools. Earle L, Kelly L. Coping Strategies, Depression and Anxiety among Ontario Family Medicine Residents. Canadian Family Physician 2005; 51:242-3. Cohen J, Patten S. Well-being in residency training: a survey examining resident physician satisfaction both within and outside of residency training and mental health in Alberta. BMC Medical Education; 5(21). Levey RE. Sources of stress for residents and recommendations for programs to assist them. Academic Med 2001; 70(2):142-150.

Trends in the development of flexible thermal protection systems for modern aircraft

2020 ◽  
pp. 10-21
Author(s):  
V. G. Babashov ◽  
◽  
N. M. Varrik ◽  
Keyword(s):  
High Temperature ◽  
Thermal Protection ◽  
Heat Removal ◽  
Operating Conditions ◽  
Passive Protection ◽  
Thermal Protection Systems ◽  
Heat Protection ◽  
Protection Systems ◽  
Protected Surface ◽  
Flexible Panels

The emergence of new types of space and aviation technology necessitates the development of new types of thermal protection systems capable of operating at high temperature and long operating times. There are several types of thermal protection systems for different operating conditions: active thermal protection systems using forced supply of coolant to the protected surface, passive thermal protection systems using materials with low thermal conductivity without additional heat removal, high-temperature systems, which are simultaneously elements of the bearing structure and provide thermal protection, ablation materials. Heat protection systems in the form of rigid tiles and flexible panels, felt and mats are most common kind of heat protecting systems. This article examines the trends of development of flexible reusable heat protection systems intended for passive protection of aircraft structural structures from overheating.

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